To improve severe thunderstorm prediction, a novel pseudo-observation and assimilation approach involving water vapor mass mixing ratio is proposed to better initialize NWP forecasts at convection-resolving scales. The first step of the algorithm identifies areas of deep moist convection by utilizing the vertically integrated liquid water (VIL) derived from three-dimensional radar reflectivity fields. Once VIL is obtained, pseudo–water vapor observations are derived based on reflectivity thresholds within columns characterized by deep moist convection. Areas of spurious convection also are identified by the algorithm to help reduce their detrimental impact on the forecast. The third step is to assimilate the derived pseudo–water vapor observations into a convection-resolving-scale NWP model along with radar radial velocity and reflectivity fields in a 3DVAR framework during 4-h data assimilation cycles. Finally, 3-h forecasts are launched every hour during that period. The performance of this method is examined for two selected high-impact severe thunderstorm events: namely, the 24 May 2011 Oklahoma and 16 May 2017 Texas and Oklahoma tornado outbreaks. Relative to a control simulation that only assimilated radar data, the analyses and forecasts of these supercells (reflectivity patterns, tracks, and updraft helicity tracks) are qualitatively and quantitatively improved in both cases when the water vapor information is added into the analysis.

The 11‐year solar cycle (SC) has been widely recognized as a potential source of regional climate variability in the Northern Hemisphere winter. However, whether an SC signal exists in the southern China winter precipitation remains unclear. By analyzing land surface precipitation and sunspot number data from 1901 to 2010 in this study, evidence of a robust positive precipitation response that is synchronous with the SC in late winter (January–March) over southern China is provided, and the most statistically significant signals (p < 0.01) are detected over the middle Yangtze River basin. In early winter (October–December), there are only nonsignificant negative responses. The late winter SC‐precipitation relationship persists over time and appears to largely result from a solar‐associated Rossby wave train originating from the North Atlantic/European region. Our results indicate an enhanced predictability of late winter precipitation over southern China.